Safety system for operating railroads.



PATENTBD JUNE 19', 1966.

1 v W..H. DAMMOND. I

. SAFETY SYSTEM FOR OPERATING R-AILROADS.

APPLICATION PILED'TBB. 17. 1905.

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I lure-70? W1 rwsaaz-s m. 823,513. PATENTED JUNE 19,1906.

' W. H. DAMMOND.

SAFETY SYSTEM FOR OPERATING RAILROADS. 'AB'PL'IOVATION FILED FEB. 17. 1905.

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. -UNITED STATES" ParE T OFFICE...

I'VILLIAM H. DAh IMOND, OF DETROIT, MICHIGAN.

SAFETY SYSTEM. FOR OPERATIQNG'RAILROADIS.

Specification of Letters Patent.-

Patented June 19, 1906.

Application filed February 17, 1905. Serial No. 246,037.

- Railroads; and Ideclare the following to be a full, clear, and exact-description of the Invention,'such as willenable others skilled in the art to which it pertains to make and use the same, reference being had to the aCCOl'X k. panymg draw1ngs, ,wh1ch for'n a part of this specification.

the length of the block. These receiving,

My invention relates to systems for controllingthe motion of trains; and the objects of my improvement are to produce at any desired point on a car, train, or locomotive distinct results corresponding to the conditions clear, ,caution, and danger of the track ahead of said car, locomotive, or train.

These and other objects I obtain by the safety system hereinafter described more fully and claimed, and illustrated by the accompanying drawings, in which- Figure 1 shows a practical arrangement of track-circuits; Fig. 2, another practical method 'of distributing the receiving points or stations on the track than t at shown in Fig. 1, and Fig. 3 shows the mechanism of the receiving car, locomotive, or .,tra1n, together with one setof results that may be produced corresponding to the condition clear, danger, and caution of the track ahead.

At various points along. one of the trackrails are located homereeeiving points or stations, the distance between two consecutive receiving-stations determining at that place stations may preferably consist ofportions of the track-rail insulated from the-adjacent portions thereof, and the side of the track on which these 'recciving-points. are located is hereinafter designated the -home side of the track. Besides the home receivlng-pomts I preferably provide 1n each block a distant receiving point or station, which I preferably locate on the rail not containing thehome.

receiving-points, and the side of the track on which such distant receiving-polntsare located is hereinafter designated the distant I side of the track. These distant receivingpoints, like the home receiving-points, may preferably consist of portions-of the track-rail insulated from the adjacent portions thereof.

These home and distant receiving-points may 5 5 tant results are produced on said conveyance when the latter arrives at-a predetermined end of the second block preceding the obst ucted block.' In Fig. 2, however, it will be noted that while, as in Fig. 1, the home receiving-points ac bb, &c., are located near t e ends of the blocks immediately preceding the .obstructed block the distant receiving 'points bb 0'0, 620., unlike the case of Fig. 1, are located at the-ends of thesecond block preceding the obstructed block. In other words, the distant receiving-point for any blockand the home receiving-point for the next block ahead are locatedat the same position along the length of track directly protected. It will be noted that in Figs. land 2 the blocks are lettered I, II, III, and IV, the direction of trail-lo in each case being as indi- 1 point between the endof the first and the cated by the arrow. In block III it will be noted that key k in Fig. 1 and key is in Fig. 2 appear, which are omitted "from. the wiring of the other blocks. These keys are not necessary to the purelyautomatic block safety operation of the system. Their utility will ap )ear below.

In block III, Fig. 1, islocated a track-batftery z, from which a circuit. extends from one pole to conductor 20*, to key Ir, to conductor 20, to track-rail CC, to bonding-wire 12 to track-rail C, to conductor 42, to coil of track-relay r, to conductor 43, to track-rail H, to conductor 1;, to track-rail K, to conductor 22, back to battery 2. Track-relay 1' being energized, as just shown, closespartial circuits from batteries 2 and z to the receivingpoints in the preceding block. One of these partial circuits is from one pole of 2 to conductor 36, to insulated relay-contact r, to conductor 37, to receiving-point a and from the other pole of .2 to conductor 38, to track-rail H, and. thence through track-rails H K, &c and bonding-wires y y, &c., to any point, exclusive of distant receiving-points, on the track rail on the dis tant side of the track. The other partial circuit here is from battery 2, to conductor 39, to insulated relay-contact T to conductor 40, to distant receiving-point at, and from the otherpole of battery 2 to conductor 41, to track-rail B.

On. each conveyance on which the desired results are to be produced I provide a home contact L, which may be an insulated wheel or the like, and a distant contact M of similar construction Thesecontacts. may be selected from the regular wheels-of the conveyance, properly insulated, or may consist of extra wheels, as may be desired. In any case, however, they must be insulated from each other and from the remaining portions of the vehicle, the-distant contact orwheel being so arranged as to travel on the rail on the distant side of the track and the home contact on the rail on the home side of the track. Suitable contacts land m are provided by which current may pass from each of these insulated wheels to conductors on the locomotive or car. The operating instrument, located at any convenient point on-the conveyance and shown in Fig. 3, is divisible into a home and a distant section. The distant section of the instrument contains .a main armature N and an auxiliary armature N, adapted-to make certain contacts, as shown below, and controlled as to position ,bycertain electromagnets; as hereinafter described. In the home section of the operating instrument is the mam home :armature O and the auxiliary armature O, arranged to-make certain contacts and to be controlled in position by certain electromagnets, as hereinafter shown. It will be noted that on one end of the main distant armature N is a contact a, which is insulated from said armature N. 'lhiscontact may CODSlSQOf any suitable kind of conducting material and is designed to cooperate with two pieces of conducting material, which are insulated. from each other and which constitute the circuit-lneaker n -,Thus if the armature N is rotated to the dotted position and the circuit supplied by the wires land 2 is complete, except for the opencircui ttbetween the halves of the circuit-breaker ;n. ,.then this circuit will again become'closed when armature N is suitably rotated, so that contact 12. touches simultaneously the halves of the circuitbreaker M, as shown in the full position of the armature N. At one end of the ,main home armature O and at each end of the auxiliary I ted position.

'turn is effected at the proper time by the coarmature, and these contacts shown tor the" other armaturcs operate in conjunction with their respective circuit-lneakers in manner similar to that just described for the main distant armature.

In addition to the contacts just explained it will be observed the main distant ar1nature N carries two other contacts 12" and a which alternately close circuits containing the circuit-breakers n and 117. These contacts are insulated from the armature N. The main home armature O carries a contact a", similar in construction and insulated siiiilarly as just shown for the contactpieces a and a for the main distant armature. This contact n on the main home armature alternately opens and closes the circuit through the circuit-brcnher a, uccording to the position of the rotating armature O. i

A rctaining-elcctromagnct P is provided for the main distant armature N, which is supplied from a battery I. When the armature N is once rotated to the dotted position, a circuit through this retaining-magnct is established by way of contact 1) and the armature N. Hence if the circuit: from battery P and around magnet I is opened at any other point than between contact p and the armature N and said armature underthe cl"- fect of gravity or of springs, for instance, drops to the full position, then even when the former open circuit is closed there remains the open circuit between contact 1) and armature N, and the retaining-magnet I will therefore remain deenergizcd, and hence unable to return the armature N to the dot- As will appear later, this re.-

operation of the magnets Q and S or the. cooperation of magnets V, V, and Q.

In case there is not Sll'llHlGHt and proper ditl'erence of mechanical moments between the halves of the respective armatures to cause them under the ellect of gravity to return with requisite proinptness to their full positions the proper ends may be suitably weighted or springs may be supplied for this purpose.

, It is evident that when the keys 7. and It? in block III, Figs. 1 and 2, are closed the electrical circuits in this block are essentially the same in each case as the showin for the other blocks. In other words, the ell ect of opening and closing key is, Fig. l or key It, Fig. 2, is the same for block II as will be produced in block III by opening and closing relays r, Fig. 1, or rr, Fig. 2.

One way of promoting the safety of trains viding "a signal containing three indicators one, D,- meaning .caution,- another, W, ,meaning clear, and another, R, meaning- These three indicators may be arranged behind a screen which covers the frontof the indicator mechanism in such manner that normally the red or danger signal 'is displayed through .an opening in the screen. ;,Olear and caution indicators Wand Dzmay be'su ported normally away from the opening'in t e screen on hang '.ers providedwith armatures adaptedto, be

In this way'when. armaturesO' and N are both in the "dotted positions current from battery A supplies a circuit to conductor through circuit-breaker n bycontact n, to

I conductor 34-, through-onehalf of circuitbreaker n, to conductor 53, through circuitbreaker n by contact a, to conductor 21, tov

inagnetw, attractin clear indication W to cover R and be t us displayed, then to grounded wire 52, the other half ofthis' circuit being from battery A tofgrounded wire 50. If armature O wereto remain in the dotted position and armature N dropped to the full position while battery A-fwould remain grounded on one side through conductor 50, yet the circuit on the other side of this battery would now be from A to conductor 35, through circuit-breaker n,,by contact n",

then to conductor 34, through a by contact W, to conductor 51,- around magnet 11;, causing said magnet to attract D, obscuring R and d-isplayin D,- thento common conductor, a 52 to a groun ed portion of the locomotive or car. Ii armature O now'be in full position, then battery A isopen-circuited ,at the cir'-' cuit-breaker-n, and hence nomatter what the magnet a, controlling indicatonW, and mag i position of -'N current is cutoff from both net a:, controlling D, and hence the danger- I signal-Rremainsdisplayed. When armature from the display of '0 remains in the dotted position, it will gen erally be desired in ractice that the change oppositely s all be eflectedodirectly'thatis,

v withoutR intervening. This may be effected by so arranging circuit-breakers n fandn, together with their respective contacts, that in its rotation-between full and dotted posi- -tions armaturie N will always make the new contact before breaking the old one. c I

To show the operat o'n oftmy system, let

it be assumed that a locomotive properly to the display of D and equipped isinblock II, Fig. 1', at'a point behind distant receiving-point a/that is,.sup'- pose that this distant-point is between the 10- comotive and the home receiving-point a and that the clear results are being produced on thelocomotive; also, let the block III be clear." Now whenonce the main distant armature N'is sent to the dotted position and. the auxiliary armature N is down in its normalv (full) position the main armature is maintained in said-clear(or dotted) position by magnet P, which is sup lied from battery P, the circuit vbeing from attery P toconvductor 3, to electromagnet P, to conductor 4,,

to contact5, to contact'fi, to armature N to conductor ;7-, to conductor 8, to brushm, to insulated wheel M, to track-rail G, to uninsulated locomotive-wheel M, to conductor 13, to conductor 10, to armature N, to contactp, to conductor-11, back to battery P Again once the main home armature O is rotated to the clear (or dotted) position it'is 1nain-.

tained in that position by the honieretaining-magnet P, which is energized by current fromretaining-battery P, the circuithere being from battery P to conductor 12, to contact p, to retaining-armature O, to conductor 13, to .uninsulated locomotive wheel L, to track-rail B, to homecontact L, tobrush Z, to conductor 14, to conductor 15, to armature O, to contact 16, tocontact 17, to conductor 18, to electroma net P, to conductor'lQ, back to battery P When the lo comotive [advances to such position as to cause contact M to be in the insulated section a the circuit. around retainingmagnet P is,

chan ed between contact-wheel M and wheel M, t 1e circuit being nowirom' battery P lto conductor3, to ,ele'ctromagnet P, to conductor 4, to contact 5, to contact 6, to armatureN to conductor 7 to conductor 8, to brush m, 'to' wheel M,to receiving-point a to conductor 40, to insulated relay-contact 1*,to conductor 39,

through relay-controlledbattery z to conductor'41, to track-rail B, to wheel'M, to conductor 13, to conductor 10, to armature N, to contact p, to conductor 11, back to bat-f tery I This position of the locomotive causes the relay-controlled battery 2 and the retaining-battery P to supply the'same cirrcuit, and in order that armature N shall not drop to the full position, giving a false cau-.-

tion result, two alternatives maybe chosen from:v either the relay-controlled battery 2 and the retaining-battery 1" may be connected, so that opposite poles are grounded, thus causing relay controlledbattery to be thrown .in series" with the retaining-battery P in the position of locomotive now considered, erre lay-battery ma bemade sufliciently weaker ,than-retainingattery so as to cause the re-' sultant electromotive force of the two when I connected in opposition to be sufficient to magnetize retaining-magnet P with such force as to cause P to continue holding arma ture N in the dotted position. As-the train proceeds so that the contact M leaves the insulated section a, then the instant said Wheel M is in contact with both receiving-point a and the track-rail current from relay-controlled battery z is shunted by wheel M from a to track-rail H by uninsulated wheels and I axles to track-rail B, to conductor 41, back to battery 2, and the circuit from retaining-battery P to magnet P is reestablished by the above-described partial circuit to m, to M, and thence through track rail H to conductor y, to track-rail G, to any uninsulated wheel of'the locomotive, to conductor 13, and thence by partial circuit above described through conductor 10, armature N, conductor 11, &c., back to retaining-battery P When the locomotive proceeds sogthat wheel M leaves distant receiving-station a, then the circuit from battery P to retaining-magnet P will continue completed through trackrails and bonding-wires on the distant side of the track, as above explained. In this waymagnet P continues energized, and in consequence circuit to si nal-magnet {I} will remain closed'so long as t e locomotive remains in block II in advance of the home receivingpoint a. When the locomotive advances to suoh'a'position that L enters the home receiving-point a, then the relay-controlled battery 2 is thrown into the same circuit with the retaining-battery P the two batteries being either 50 connected as to be in series or so re- I lated to each other and to the magnet P as-to cause P to continue holdin mature O in the dotted position, the circuit here being from battery P? to'conductor 19, to magnet P, to conductor 18, to contact 17, to contact 16, to armature O, to conductor 15, toconductor 14, to brush Z, to wheel L, to receiving-point a, to conductor 37, to insuelectromotive force and magnetomotive force that the resultant effect of said batteries is to main home ar' lated armature contact W, to conductor 36, v

to relay-controlled battery 2, to conductor 38, to track-rail H, to wheel L, to conductor 13, to armature O, to contact to conductor 12, back to battery -P Vi hen the loco motivecontinues its trip-until L touches BB, then current from P passes to conductor 19,

through retaining-magnet P, to conductor 18, to contact 17, to contact 16, to armature O, to conductor 15, to conductor 14, to

- brush Z, to wheel L, to track-rail BB, to conductor to'traok-rail B, to wheel L, to conductor 13, to armature O, to contact p, to conductor 12, back to retaining-battery P.

y the process just-described the locomotive will. enter block III with the clear results thereon continuing, and'the cycle above detailed will recommence.

To explain the behavior of the system under another practical conditionfsuppose, as before, that the clear results are effected and the position of the locomotive such as to rail B; but suppose, differently from t to key is, to conductor 20, to track-rail CC, to

point a.

stasis cause the distant contact M to be on the rail G, thehome contact L being on the opposite e previous case, that block III contains a car or en ine constituting an obstruction in block II In this case current from track-battery- 2 is shunted away from coil of track-relay r by the obstructing wheels and axles, the circuit being from battery 2 to conductor 20,

conductor M, to track-rail C, throu h obstructing wheel and axle to track-mi H, to conductor y, to track-rail K, to conductor 22, back to battery 2 As armature of trackrelay 1" is now in its open position, the circuit controlled by relay-battery z will be opened at said relay. Hence when the locomotive moves to such a position as to cause distant contact M to enter the distant receiving-point a the circuit from distant retaining-battery P through retaining-magnet P will be broken between M and M as the former is separated from the latter wheel by the insulation b which a is separated from adjacent rails and H. Hence retaining-magnet P being deenergized main distant armature N will now drop from the dotted position to the full position. The circuit to the apparatus for pro ducing the clear results being now opened at circuit-breaker n and that for producing the distant or caution results being closed by n, connecting the halves of circuit-breaker n,

the clear results will now cease and the distant or caution results will be efiected. Thus,

a ain using the aforementioned signals as an il ustration, circuit to magnet a; will be opened at circuit-breaker n and circuit to magnet ac will be closed through clrcuitbreaker n by contact 11*". Hence clear signal W will be obscured and caution-signal D will 10 5 show through the opening in the screen at the same time, obscuring danger-si nal R.

- point a and until the locomotive proceeds so 1 1o far as to cause the home contact L to enter the home receivin point a, then the circuit from battery P to ome retaining-magnet P will be broken at L, since contacts ofrelay 1' being open current cannot now passfrom n 5 home receiving-point a. Thus 't e circuit through the apparatus capable of producmg the clear or caution result will be open at the circuit-breaker n and would remaln so were the locomotive to proceed until a distant si 12o naling-point having clear track immediate y ahead were reached. Now in obedience to the danger results if they did not include such as to stop the locomotive automatically the engineman would stop the locomotlve wlth m 5 the home contact in the home recelving- When the obstructing train, car, or

en ine leaves block III, sothat it becomes sa e for the locomotive in block II to pro- .ceed, then current from :4 being no longer 0 shunted by the obstruction that was in block III will flow from battery .2" to conductor to key 76, to conductor 20, to track-rail CC, to conductor 71", to track-rail C, to conductor 42, to coil of relay r, to conductor 43, to trackrail II, to vconductor y, to track-rail K,.to

I conductor 22, back to track-battery z. This current will energize coil of relay 1", causing said relayto close a circuit from relay-controll ed'battery 2, this circuit being from relaycontrolled' battery 2" to conductor 36 to insulated armature-contact T to conductor 37, to home point a, to home contact L, to brush Z, to conductor14, to conductor 27, to conductor 28, to returning-magnet V, to conductor 29, to conductor 44, through circuitbreaker p by contact 11 to conductor 45, to

conductor 18, to wheel L, to track-rail H, to conductor 38, back to relay-battery 2' At the same time themultiple circuit-branching from that ust given between conductor 27 and conductor 29 will be energ zed, the c1r cuit being from conductor 27 to conductor "46, toreturning nagnet V, to conductor 47,

back to naincircuit at conductor :niagncts V and V are now energized armatures O and X will be attracted tothe dotted positions, causing contacts t and t to close circuits through circuit-breakers T and T. and causing c1rcu1t-biehker 'w to close'a partial circuit through the circuit-breaker w. Battery U Wlll now energize returnlngmagnet Q, the circuit being 'frorn battery U to conductor 24, through ci-rcuitbreaker T bycontact t, toconductor 25, to magnet Q, to conductor .26, back to battery'U. At the same time battery energizes returning;

magnet Q, the circuit being from battery to conductor 31, through circuit-breaker by contact if, to conductor 32, through magnot Q, to conductor 33, back to battery Q This will cause armatures N and'O to be attracted by magnets Q and Q to the dotted.

to saidV andV are opened at circuit-breaker the new partial clrcult being from conductor 44, through circuit-breaker w by contact w, to comluctor 30, back to the previous route byconductorl3. Armatures N and Obelng 'now in the clearer (lottefl osition the clear results will be effected, ass own'before, and the lomnnotive will proceed to ,block III. When the home contact leaves the receivingpoint (t and enters track-rail BB, current from relay-controlled battery 2 to magnets V and V will be cutoff at the insulation, s'ep arating receiving-point a from the adjacent track-rail sections. Hence magnets ,V and V being deenergized armatures N and 0 W111 drop to their normal or full positions; but

the parts are so arranged that contact 16 will touch contact '17 before it o ens the circuit through circuit-breaker T. 1 11 other words,

the circuits above described from battery P? tomagnet P and from battery P throu h magnet P by way of contacts and p"will e reestablished between ,M and hi on one side and L and L on the other side, and as wheels M and M are now'connecte'd by track-rail v BB the circuits from batteries 1? and 1? will now be com leted through magnets P and P and the eye e above detailed as begimiin in block II will now recommence. in block II As it fre uently occurs in racticethat struction on the lock immediately ahead forinstance, when thectrack becomes insecure, but does not interfere with the circuits for the foregoing automatic operation of my systemthe ke s k, Fig.1, and 7c, Fig. 2, are provided, by w 'ch circuit fromvrelay-con- 7 trains shoul sto even whent ere is no obtrolled batteries may be opened. Thus when an operator desires to stop a train ahead of which there is no obstruction he has but to open key It or is, thus cuttin ofl current from receiving-points behind an the roper caution and danger results .will be 'effbcted on a following train, car, or engine as the latter enters the signal-points aflected, as shown above.

It may sometimes be desired toreturn from a caution to clear results while i the receiving-locomotive is on a distant receiving-point, and for this purpose I provide the partial circuit from M to brush m, to conductor 8, to conductor 23, through magnet S, to conductor 1, through circuit-breaker n by contact at, to conductor 2, toconductor 10, to

conductor 13, towheels M and L. It will be evident that this partial circuit may affect through distant receiving-points, v track-rails, and bonding-wires y y, &c., control of returning-magnet 'S by circuits from relaycom trolled batteries 2; 2" 2 :2, &c., in manner circuits, as above shown, from battery z ,by ay completing partial'circuit is offered from conductor 1, through one-half of circuit-breaker n, to conductor 48, through circuit-breaker vn by contact 'n, to conductor 49. and back to the circuit through magnet Saridb way of circuit-breaker n "conductor 2, c. The contacts..5 f and 6, circuit-breakers 11?, T, and

a are arranged in the same relative positions.

as the showing above detailed for contacts 16 and 17 circuit-breakers T, w, a'ndg".

Referring to Fig. 3, armature may be used for the en 0, is up inthe dotted posiof home receiving-point a. .When cir-. cuit from relay-battery through S is opened atcircuit-breaker n then, similarly as shown for circuit-breakers w and pi, an alternative purpose of so controlling two I valves that w tioii one of these valves is open and the other I 10 similar to the control of magnets V and V by closed, and when 0 is down in the full position the former valve is closed and the latter 0 en. The last-named valve may be used to e set the emergency application of the airbrakes, while the other valve is inserted in piping leading from the boiler to the cylinders of a locomotive. Armature .N may be employed for-similarly operating two valves, one being inserted in the same steam-piping with-the steam-valve controlled by O and only partly closed when N is down in the full position, While the other valve is used for effectinga relatively light application of the air-brakes. Then when both N and O are up in the dotted position both steam-valves are fully open and both air-valves are closed. Hence the train will be permitted to run at full speed. If N is'down in the full position and 0 up in the'dotted position, steam is partly shut off (by the valve controlled by N) and a. lightapplication of the air-brakes made, so that the train is automatically slowed down. If 0 is down in the full positrolled by 'O') and anemergency application tion, then no-matter what the position of N steam is shut-off (by the steam-valve conof the air-brakes made.

It was set forth at the beginning of this specification that one of my objects was to 30 produce definite results on the locomotive, car, or train corresponding to the condition of portions of the track ahead. It was also explained above that among such results my invention includes control of signaling apparatus. In thevalve operation just detailed is illustrated how automatic operation of speed-controlling. mechanism is also included means by which to signal three distinct in-.

structions for a block, switching means on said vehicle and controlling the circuit to sald electromechanical means in such manner that when said switching means is in a predetermlned POSltlOIl said electromechanlcal means is prevented rrom permitting a certain one oi said instructions to be sig-- naled.

2. A vehicle adapted to travel on electrically conducting track rails, suitable trackcircuits, electromechanical means carried by said vehicle and in circuit with an electrical source on the vehicle, the circuit to said electromechanical means being operated bythe track-circuits and capable of operating means for signaling in any block to-stop, to slow down, or to run at full speed, according to conditions obtaining at predetermine places, switching means on said vehicle and controlling the circuit to said electromechanical means in such manner that when said switching means is in a certain position said electromechanical means is thereby prevented from permitting said signaling means to indicate to run at full spee 3. In a safety system for railroads, a track/ containing insulated sections, a vehicle thereon provided with insulated contacting means adapted to make electrical contact with a track-rail, a partial electric circiiit on the vehicle including an electric source thereon and containing a portion of track-rail and an un- 5 insulated portion of thevehicle, said insulated contacting means causing said partial circuit alternately to become closed through a portion of track-rail and to be thrown in circuit with a partial circuit extraneous to 9 the vehicle, electromagnetic means on the vehicle tor producing a definite result thereon andadapted to operate independently of the direction in which current is supplied thereto, said electromagnetic means being controlled by the partial circuit on the vehicle when said partial circuit is closed through said track-rail portion, or is thrown inv circuit with the partial circuit extraneous to the vehicle, substantially asdescribed.

4. A track containing insulated sections of rail a vehicle thereon supplied with insulated contacting means, a partial electric circuit on the vehicle supplied. from an electric source thereon, electromagnetic means on 95 the vehicle controlling electromagnetic devices for producing definite results thereon and in turn controlled by the partial circuit being closed, a partial circuit'from a source of electricity extraneous to the vehicle and including contacting means on thctrack insulated from adjacent portions of track-rail, said insulated contacting means of the vehiole-and uninsulated portions of said vehicle being. adapted to complete said partial 'cir- 5 cuit from said extraneous source through electromechanical means on the vehicle for closing the circuit controlling said electromagnetic means.

5. In a safety system for railroads, a track containing insulated sections, a locomotive or car thereon carrying insulated contacts adapted to travel on the track-rails, electromagnetic means for producing on the locomotive or car definite and distinct results 5 corresponding to-the conditions clear, caution and danger of predetermined portions of the railroad in such manner that the danger result will be produced when current controlled by said electromagnetic means 1 0 ceases, circuits from a i'electric source on the locomotive or car and including the insulated contacts controlling the current to the'electromagnetic means for producing the clear,

danger and. caution results thereon, and electrical means on'the track and extending bedetermined b insiilatiin means between sec tions of track-rail, contacting [means in a block and insulated from ad acent portions of track-raiha source of electricity electricwhen the vehicle-contacting means touches ally connected to track-rails on opposite sides of the track in a block means adapted to be supplied with current from 'said source and controlling a partial circuit from an electrical source to said insulated contactingfmeans and to a track-rail in such manner that said partial-circuit shall be broken when said controlling means is denergized, the circuit-controlling means so communicating with, said electrical source connected to said opposite tracki'ails that current 'from said source shall be shunted away from the controlling means when an electrical conductor connects rails on opposite sides of'the track in the block to' rails of which'said electrical source-is con nected, a vehicle on the track provided with insulated contacting means adapted'to travel on a track rail, means on the vehicle for prod ucing definite results thereon and electrically connected to uninsulated portions of the vehicle andto the insulated contacting means thereof, said means for producing the results being adapted to produce a certain 'result an insulated track-contacting means thesaid controlled artial circuit to which is unbroken an( to produce a different .result' when the insulated contacting means of the vehicle touches an insulated track-contacting means the said controlled partial circuit to which is broken, substantiall as described.

7. In a safety system for rai reads, a locomotive or car, a source of electricity thereon, a switching device for causing theelectric source alternately to supply current to either or both of two circuits for producing certain results on. the locomotive or car and to open j said electric circuits, electromagnetic means 7 on the locomotive or carsupplied from an electrical source thereon for controlling said switchingdevice, electromagnetic ineans on said locomotive'or car for diverting the current from an electrical source thereon to one or bothof the circuits for producing said results, insulated contacts on the locomotive or car 'and-in the circuits controlling said switching and diverting devices by whichsaid circuitsma be completed through rails of the track am iininsulated portions of the locomotive or car. 7

8. v In a safety system for railroads, adiverting device on a locomotive or car by which current from an electrical source thereon may be'supplied to either or botli'cl two devices for'p'roducing results corresponding to the conditions clear and eautimi ahead,

electromagnetic means for controlling said said controlling means is (-lH-JglZQd it will cause the divertingdevice to send current to the devices for producing the results corresponding to clear ahead and when sa d controlling means is deenergized it will cause the diverting means to send current to the devices for producing the results corresponding to caution ahead, a switching device in the circuit to said means for controlling the diverting device such that when circuit to said controlling means is once opened at any other point said switching device will itself open' and thus prevent subsequent closing ofsaid circuit at said other point from again completing the circuit to said controlling means, means-0n said locomotive or car adapted to receive current from an electrical source extraneous. to said locomotive or car which when energized will close a circuit through said device for controlling said diverting device when the circuit by way of sai switching device is open at any other 'point and will cause said controlling device to'remain closed until said other open circuit shall have become closed. I

9. A source of electricity on a locomotive or car, electrically-controlled means on said vehicle forproducing predetermined results thereon corresponding to conditions obtaining at a predetermined portion of 'a railroad, a switching device for operating a circuit from said electrical source, said cir- -cuit being adapted to actuate said electrically controlled means and said switching device in turn so influenced by said electrically-controlled means that in case the vice will itself become open and thereby pre-' vent the said circuit from becoming complete on the closing of the open circuit at said other point.

electromagnetic diverting device in such a manner that when 10. A source of electricity on a locomotive or car, electrically-controlled means on said vehicle for producing predetermined results thereon corresponding tov conditions obtaining at a predetermined portion of a railroad, a switchin device for operating a'circuit from said e ectrica] source, said circuit beingadapted to actuate said electrically-l controlled means and said switching device in turn so influenced'by said elcctrically controlled means that in case the circuit from said electrical source to said controlled means is opened at any other point than at cuit at said other point has become closed said switchingdevice, said device will itself i through a predetermined partial circuit. [0 become open and thereby prevent the snid In testimony whereof I sign this specificacircuit from becoming complete 'on the clostion in the presence of two witnesses.

ing of the open circuit at said. other point, WllililAM H. DAMMOND. electromagnetic means adapted to cause Witnesses:

said switching device to close at the proper S. E. THOMAS,

time and to remain closed until the open cir- ALLAN Molinmis; 

